The present invention relates to a rotary throttle member for a fuel admission system of an internal combustion engine, the throttle member being of the type comprising a shaft having cylindrical bearing surfaces straddling a section for receiving a butterfly valve member. An application that is particularly important, but not exclusive, lies in throttle body assemblies for fuel injection systems.
Conventionally, a rotary throttle member for an admission system consists of a shaft and a butterfly in the form of a flat disk, both being made of metal. The butterfly is held in a slot or on a flat of the shaft by means of screws. The manufacture of such a member by machining and assembling is expensive.
In addition, experience has shown that under unfavorable atmospheric conditions frost is prone to attach to the metal parts and in particular to the connection zones between the butterfly and the shaft.